# Copyright 2025 Google LLC
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

"""
Main FastAPI application entry point for the Quick Bot Backend.

This module initializes the FastAPI application, configures CORS based on
the environment, defines root and version endpoints, includes API routers
(e.g., for search functionality), and provides an endpoint for audio
transcription using Google Cloud Speech-to-Text.
"""

from fastapi import FastAPI, File, UploadFile
from fastapi.middleware.cors import CORSMiddleware
from src.controller.chats import router as chat_router
from src.controller.intents import router as intent_router
from src.controller.models import router as model_router
from google.cloud import speech
from os import getenv


app = FastAPI()


def configure_cors(app):
    """Configures CORS middleware based on the environment."""
    environment = getenv("ENVIRONMENT")
    allowed_origins = []

    if environment == "production":
        frontend_url = getenv("FRONTEND_URL")
        if not frontend_url:
            raise ValueError(
                "FRONTEND_URL environment variable not set in production"
            )
        allowed_origins.append(frontend_url)
    elif environment == "development":
        allowed_origins.append("*")  # Allow all origins in development
    else:
        raise ValueError(
            f"""Invalid ENVIRONMENT: {environment}. 
            Must be 'production' or 'development'"""
        )

    app.add_middleware(
        CORSMiddleware,
        allow_origins=allowed_origins,
        allow_credentials=True,
        allow_methods=["*"],
        allow_headers=["*"],
    )


# Create a route to handle GET requests on root
@app.get("/")
async def root():
    return "You are calling Quick Bot Backend"


# Create a route to handle GET requests on /version
@app.get("/api/version")
def version():
    return "v0.0.1"


@app.post("/api/audio_chat")
async def audio_chat(audio_file: UploadFile = File(...)):
    client = speech.SpeechClient()
    audio_content = await audio_file.read()
    audio = speech.RecognitionAudio(content=audio_content)
    config = speech.RecognitionConfig(
        language_code="en-US",
        sample_rate_hertz=48000,
        model="default",
        audio_channel_count=1,
        enable_word_confidence=True,
        enable_word_time_offsets=True,
    )

    operation = client.long_running_recognize(config=config, audio=audio)

    print("Waiting for operation to complete...")
    response = operation.result(timeout=90)
    print(response)

    text = ""
    for result in response.results:
        print(f"Transcript: {result.alternatives[0].transcript}")
        text = result.alternatives[0].transcript

    return text, 200


configure_cors(app)

app.include_router(chat_router)
app.include_router(intent_router)
app.include_router(model_router)
